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Transmission leaks

Started by Anthony, November 02, 2006, 11:03:59 PM

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I have a '79 TA with a freshly rebuilt TH350 trans and a B&M shift kit that I recently installed. After adding fluid and test driving the car everything appeared OK, with the fluid level reading just at the operating range on the dipstick, vehicle in park running and warm. I usually only run the car once a week so when I looked at it mid-week it was OK but when I looked at it after a week there was a puddle under the trans. Is this common with these transmissions?

I don't think its overfilled. I also changed the trans pan and gasket as well as replacing the cooling lines with OEM steel lines (someone used rubber hose at some point.) I can live with a little leak but I don't want to be replacing this trans again because of some unseen problem.

Any info would be greatly appreciated.

Jim K.
Black 2001 Trans Am WS-6
SLP longtube headers, loudmouth exhaust, SLP frame connectors, B&M shifter, Eibach lowering springs, few other goodies here and there.


How large was the puddle? If it was less than 3" across it is probably the front seal leaking a bit after it sits. That tends to happen when they aren't driven. The places a TH350 can leak are the pan, front pump to case, shifter quadrant, kick down cable, servo covers, cooler lines, speedo cable, tail shaft housing, and rear seal.

The most often leak areas are an over tightened pan, front seal, cooler lines, and shift quadrant. The pan bolts don't get much torque on them, only around 10-14 ft lbs, that isn't much. If you cranked them down more than that, the pan is almost positively leaking. Jack the car up and take a look. Find out what side of the trans the leak is on. Then you can go about stopping the leak.
Todd Stahr
National Firebird and Trans Am Club
phone/text: 773-769-7166

North America's oldest and largest club for all Firebirds and Trans Ams including GTAs and Firehawks.  Established in 1984 and offers color magazines (EAGLE), emagazines, technical advice, free member classifieds, member repair shop recommendations and much more!

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